Combining bioengineering and plant conservation on a Mediterranean islet

Abstract

This paper reports the results of a bioengineering intervention within the Mediterranean Basin carried out at Lampedusa Island (Strait of Sicily) on the “Spiaggia dei Conigli”, the only sand shore of all Sicilian territory where the sea turtle Caretta caretta lays its eggs every year. The erosion of the steep slope over the beach itself caused sensitive changes in the grain size of shore’s sediment and reduced the area of the beach with fine sand suitable for C. caretta oviposition. In order to reduce surface water flow and to stop erosion, several bioengineering options were adopted using only native plant species to preserve local botanical heritage and to prevent the local extinction of some species. One year after interventions, average plant establishment was about 90% and many species which were severely endangered before the action (i.e., Jacobaea maritima (L.) Pelser & Meijden subsp. bicolor (Willd.) B. Nord. & Greuter and Limoniastrum monopetalum (L.) Boiss.) are now at low risk. Micropropagation and inoculation with beneficial root microbial symbionts were successfully applied to selected species. Regular demographic and phytosociological monitoring on permanent plot areas enabled to quantify the effect of bioengineering techniques on plant percentage cover and plant survival. The combination of bioengineering, biotechnology, and agronomic practices applied on plants appears to be effective in increasing plant cover and preserving several locally endangered plant species. Results presented here suggest that erosion can be controlled without moving large quantities of soil and without planting tree species.